8-P-Chlorophenylthio-cyclic AMP: a potent partial simulator of antidiuretic hormone action.

In the toad urinary bladder 8-p-chlorophenylthio-cyclic AMP mimics the stimulatory effects of antidiuretic hormone on osmotic water permeability, 3H2O diffusion, and transepithelial sodium transport; but unlike the hormone does not cause an increase in urea permeability. Trheshold activation for the hydroosmotic response is observed at 1 micrometer and full activation at 100 micrometer. These results suggest that cyclic AMP may not mediate all the physiological effects of antidiuretic hormone and that this highly potent cyclic AMP analog may be useful in elucidating the precise role of cyclic AMP in other biomediate hormone action.